英文别名Iso Letrozole; 4,4'-(4H-1,2,4-TRIAZOL-4-YLMETHYLENE)BIS BENZONITRILE; Letrozole USP Impurities; 4,4'-(1H-1,3,4-triazol-1-ylMethylene)dibenzonitrile; Letrozole Related Compound A; 4-[(4-cyanophenyl)-(1,2,4-triazol-4-yl)methyl]benzonitrile; letrozole regioisomer; Letrozole Impurity 1